Minself - all RAF SAR rearcrew will have undergone an extensive winching course at SARTU at RAF Valley and then completed the 6-month Sea King OCU which includes a fair amount of winching. Then, when they get to their SAR flights they, are mentored by an experienced flight training officer (Tcat) and a QHCI training officer. That is a lot of training and supervision.
I agree it is better to have the capability and not use it; but to have it and use it unwisely or poorly and cause more injury through inexperience is worse.
Proper training and current practice = no problem;
tick in the logbook and no practice = accident waiting to happen.